US4072169A - Hydraulic control system - Google Patents

Hydraulic control system Download PDF

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Publication number
US4072169A
US4072169A US05/702,860 US70286076A US4072169A US 4072169 A US4072169 A US 4072169A US 70286076 A US70286076 A US 70286076A US 4072169 A US4072169 A US 4072169A
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US
United States
Prior art keywords
pressure
valve
low
sides
medium
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/702,860
Other languages
English (en)
Inventor
Joachim Heiser
Rainer Hoheisel
Heinz Flaschar
Heinz Gand
Heinz Kleinschmidt
Konrad Braunlinger
Klaus Sopha
Roland Schempp
Hermann Sanzenbacher
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Robert Bosch GmbH
Original Assignee
Robert Bosch GmbH
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Robert Bosch GmbH filed Critical Robert Bosch GmbH
Application granted granted Critical
Publication of US4072169A publication Critical patent/US4072169A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/042—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure
    • F15B13/043—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor operated by fluid pressure with electrically-controlled pilot valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/86493—Multi-way valve unit
    • Y10T137/86574—Supply and exhaust
    • Y10T137/86582—Pilot-actuated
    • Y10T137/86614—Electric
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/8593—Systems
    • Y10T137/87169—Supply and exhaust
    • Y10T137/87177—With bypass
    • Y10T137/87185—Controlled by supply or exhaust valve

Definitions

  • the present invention relates to a hydraulic control system. More particularly this invention concerns an electro-hydraulic arrangement for connecting a source of fluid under pressure to a load.
  • a hydraulic control system wherein the high-pressure and low-pressure sides of a source of fluid under pressure, e.g. a pump, are connectable through a three-position main valve to a pair of output lines which may, for instance, be connected to opposite chambers of a double-acting cylinder.
  • a source of fluid under pressure e.g. a pump
  • the one output line is connected to the high-pressure side and the other to the low-pressure side and in the opposite end position the lines are reversed.
  • the lines are disconnected from the source of fluid under pressure and, instead, a shunt line is connected between the high-pressure and low-pressure sides to unload the pump.
  • a pressure-reducing valve Upstream of the main control valve between it and the high pressure side of the source there is connected a pressure-reducing valve whose output is connected to control valves to the low-pressure side of the source.
  • These control valves operate opposite chambers in a double-acting cylinder that is connected to the valve body and, therefore, serve to operate the main valve.
  • the main valve is carried on a single plate and there is provided on another plate an accumulator which is pressurized through a pressure-reducing valve.
  • the control arrangement including the above-mentioned pilot valves contains a solenoid valve which, when the system has not connected the main valve in either of its end positions, cuts the accumulator off from the source of fluid under pressure.
  • Another object is the provision of a system of the above-described general type which overcomes the above-given disadvantages.
  • This arrangement makes the above-described accumulator and third control valve unnecessary, so that production costs are reduced and the system is made less complex and failure-prone.
  • the position of the relatively simple low-pressure reducing valve in the shunt line insures that enough pressure is maintained in the system when it is in standby condition, that is when the main valve is in the middle position, to insure operation of the pilot valves, while at the same time the load opposing the pump of the source of the fluid is relatively small.
  • control arrangement constituted by a pair of pilot valves and the medium-pressure valve, a restriction.
  • a cutoff valve is provided between the medium-pressure valve and the pilot valves so as to cut off the medium-pressure valve from the control valve in the standby condition of the apparatus.
  • the main valve in accordance with this invention is operated by a double-acting pilot cylinder having a differential piston whose larger face is connectable through one of the pilot valves to the low-pressure side and through the other pilot valve to the outlet of the medium-pressure valve.
  • the smaller piston face is always connected to the outlet of the medium-pressure valve.
  • a high-pressure relief valve which serves mainly to protect the pump from being overloaded when the valve body is in either of its end positions.
  • a cutout valve connected to this high-pressure relief valve is effective with the valve in the middle position to cut off this high-pressure valve, but is ineffective in the other two positions so as to allow operation of this high-pressure valve.
  • the low-pressure reducing valve is effective in the central position of the main valve to maintain a relatively low pressure in the system to unload the pump while still leaving the system sufficiently pressurized to operate the pilot piston controlling the main valve.
  • the lowest pressure in the system is at the low-pressure side and this pressure is substantially equal to zero.
  • FIG. 1 is a schematic view of the system according to the present invention.
  • FIG. 2 is a schematic view of an alternate form of a portion of the arrangement of FIG. 1.
  • an electro-hydraulic control arrangement 10 has a connection plate 11 onto which is bolted a valve plate 12 and a pilot valve plate 13. To the other side of the plates 12 and 13 may be bolted another plate 14 identical to the plates 12 and 13 and at the far end there is provided an end plate 15.
  • a source of fluid under pressure constituted by a pump 48 and a reservoir 49 has a high-pressure line 16 and a pair of return lines 17 and 18, the pump 48 itself having its inlet connected to the reservoir 49.
  • the plates 11, 12 and 14 are formed with through-going passages 19, 21, and 22 that register with one another and are connected to the high-pressure line 16 and return lines 17 and 18, constituting the low-pressure side of the source.
  • a shunt line 23 connected in the plate 10 to the high-pressure side 16 passes through the plates 12 and 14 in line.
  • the shunt line 23 is connected via a one-way low-pressure reducing valve 47 to the return line 21.
  • the lines 19 and 22 terminate at the plate 15.
  • the line 16 is connected through a medium-pressure reducing valve 25, a filter 26, and a restriction 27 to a line 24 which extends in-line through the plates 12 and 14 and terminates at the end plate 15.
  • a high-pressure relief valve 28 is connected in the plate 11 directly between the high-pressure side and one return 17. This valve 28 automatically opens when pressure between the sides 16 and 17 exceeds a predetermined maximum so as to limit the pressure differential between these sides to a predetermined high-pressure differential.
  • the valve plate 12 carries a spool-type valve body 29 normally urged into the illustrated central position with its central portion 31 maintaining the line 23 open so that the valve 47 is connected between the lines 16 and 17.
  • its end portion 32 cuts off the line 23 to disconnect the valve 47 and connects the lines 16 and 17 to a pair of output or control lines 34 and 35 which may, for example, be connected as shown to a double-acting cylinder 40.
  • its other end section 33 still interrupts flow through the shunt line 23 but connects the lines 34 and 35 oppositely to the lines 16 and 17 for opposite actuation of the cylinder 40.
  • Springs effective on either ends of the valve body 29 urge it into the illustrated middle position.
  • the valve body 29 is connected via a rod 36 to a differential piston 37 connected on its other side via a smaller diameter rod 30 to a position sensor 44.
  • the small face of the piston 37 is therefore acted upon by fluid in the chamber 38 continuously connected through a restriction 41 in the plate 13 to the line 24 connected to the outlet of the medium-pressure reducing valve 25.
  • the chamber 39 at the larger piston face is connectable through a solenoid valve 42 to the chamber 38 and is connectable through another solenoid valve 43 to the low-pressure line 18.
  • These valves 42 and 43 are normally urged by respective springs into the illustrated positions, that is, allowing fluid flow from the line 24 through the restriction 41 into the line 18.
  • the controller 45 which receives an actual-value position signal from the unit 44 and a reference-value position signal from a generator 46 can operate either of these valves 42 and 43 to close it.
  • the large-diameter rod 36 connecting the piston 37 with the valve body 29 is provided with an externally projecting and diagrammatically illustrated handle 20.
  • the other side of the piston 37 is connected via small-diameter rod 30 to the controller 44 so that the effective piston surface area in the chamber 39 is substantially greater than that in the chamber 38.
  • the device functions as follows:
  • Closing of the valve 42 by operation from the controller 45 will cause the relatively low pressure in the system to become completely effective in the chamber 38, whereas the chamber 39 will remain at substantially zero pressure. This will push the piston 37 to the right and, therefore, pull the valve body 29 also to the right. As soon as the valve body 29 is off its central position, the shunt conduit 23 is interrupted and the pressure in the system will quickly rise to the level established by the valve 25, which is substantially higher than that established by the valve 47. This firmly displaces the piston 37 to the right and applies the pump pressure directly to the control cylinder 40.
  • the high-pressure control valve 28 is effective once the piston of the cylinder 40 has reached the end of its travel to prevent overloading of the pump 48.
  • valve 43 Closing of the valve 43 when the system is in standby condition will cause the relatively low pressure in the system to be effective in both of the chambers 38 and 39 and, therefore, will shift the piston 37 to the left as shown in FIG. 1.
  • the shunt conduit 23 will be interrupted and the pressure will quickly rise in the system to the level established by the valve 25 so that the piston 37 will move rapidly to the right and be held in this position.
  • the valve 42 and 43 are closed alternately; at no time are they both closed.
  • valve plates 14 may be sandwiched between the valve plate 12 and the end plate 15, these plates 14 being identical to the plates 12 and 13.
  • the restriction 41 in each of the control networks 13 ensures that the operation of the respective control arrangement will not cause a sharp drop in pressure in the system so as to prevent any of the other systems from operating.
  • a plate 60 which is identical to the plate 11 and includes the same structure except that here a simple solenoid-operated cutoff valve 62 is provided in the line 24.
  • This valve is normally closed by spring force but can be magnetically operated to open.
  • the valve 62 is controlled by the electronic controller 45 and is only operated when one of the valves 42 or 43 is electrically energized so that when the arrangement is in standby condition the line 24 is interrupted. This prevents a continuous bleed of pressure in the system through the valves 42 and 43 and considerably increases their service life. It also serves to prevent liquid loss when the valves 29 of plates 12 and 14 are operated manually through the handles 20 as this would normally interrupt the line 23 and cause a relatively heavy flow of fluid through the valves 42 and 43.
  • the system of FIG. 2 also includes a normally open cutoff valve 64 which is connected between the pilot port of the high-pressure valve 28 and the low-pressure line 17.
  • a restriction 63 is provided between this high-pressure port and the high-pressure line 16.
  • the valve 25 serves to limit the pressure at its outlet side. Thus the pressure at the outlet side of the valve 25 will never be higher than the above-described medium pressure level. This valve 25 thus closes whenever the pressure at its outlet side exceeds a predetermined medium pressure.
  • the valve 47 operates merely to create a predetermined pressure differential in one direction, while completely and always blocking flow in the other direction.
  • valve 47 in the end plate 15 a one-way valve that is provided in a separate return conduit extending from the end plate back to the reservoir 49.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Control Of Fluid Pressure (AREA)
US05/702,860 1975-07-29 1976-07-06 Hydraulic control system Expired - Lifetime US4072169A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DT2533829 1975-07-29
DE2533829A DE2533829C2 (de) 1975-07-29 1975-07-29 Elektrohydraulische Steuereinrichtung

Publications (1)

Publication Number Publication Date
US4072169A true US4072169A (en) 1978-02-07

Family

ID=5952707

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/702,860 Expired - Lifetime US4072169A (en) 1975-07-29 1976-07-06 Hydraulic control system

Country Status (6)

Country Link
US (1) US4072169A (de)
JP (1) JPS5217172A (de)
DE (1) DE2533829C2 (de)
FR (1) FR2319794A1 (de)
GB (1) GB1543182A (de)
SE (1) SE417234B (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4282901A (en) * 1978-07-18 1981-08-11 Diesel Kiki Co., Ltd. Proportional control type remote-control direction switching control valve device
US4516604A (en) * 1984-04-20 1985-05-14 Taplin John F Pilot operated supply and waste control valve
US4605042A (en) * 1983-11-09 1986-08-12 Hydrino Ab Pilot oil supply arrangement
US5463931A (en) * 1993-07-07 1995-11-07 Voac Hydraulics Boras Ab Controller for a hydraulic motor
CN104481943A (zh) * 2014-12-12 2015-04-01 吕珩 一种液压单级减压系统
CN104989693A (zh) * 2015-08-13 2015-10-21 江苏甬金金属科技有限公司 一种钢卷运卷小车升降控制系统
US20190085876A1 (en) * 2016-03-24 2019-03-21 Tadano Ltd. Hydraulic system

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5673202A (en) * 1979-11-21 1981-06-17 Diesel Kiki Co Ltd Remote-controlled valve system
DE3145720A1 (de) * 1981-11-19 1983-05-26 Robert Bosch Gmbh, 7000 Stuttgart Hydraulische steuereinrichtung zur hubwerksregelung
DE3214845A1 (de) * 1982-04-21 1983-11-03 Mannesmann Rexroth GmbH, 8770 Lohr Vorrichtung zum betaetigen eines schiebekoerpers, insbesondere des kolbenschiebers eines wegeventils
JPH02176202A (ja) * 1988-12-28 1990-07-09 Honda Motor Co Ltd 複動型油圧シリンダの作動装置
DE19526909A1 (de) * 1995-07-22 1997-01-23 Rexroth Mannesmann Gmbh Hydraulische Antriebseinrichtung

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3176954A (en) * 1961-04-13 1965-04-06 Ross Operating Valve Co Convertible valve assembly
US3556154A (en) * 1968-04-24 1971-01-19 Bosch Gmbh Robert Electrohydraulic control arrangement
US3628567A (en) * 1969-06-14 1971-12-21 Itt Power control valve
US3744374A (en) * 1971-03-17 1973-07-10 Bosch Gmbh Robert Hydraulic valve control apparatus
US3768375A (en) * 1971-02-05 1973-10-30 Bosch Gmbh Robert Control apparatus for a hydraulic consumer motor

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2958339A (en) * 1954-10-18 1960-11-01 Bendix Corp Pilot-type selector valve for hydraulic motors
DE1426606C3 (de) * 1964-05-05 1974-03-28 Guenther Dipl.-Ing. 2940 Wilhelmshaven Wessel Hydraulische Steuereinrichtung
US3502108A (en) * 1966-12-15 1970-03-24 Gresen Manufacturing Co Pilot operated valve
DE2205508C2 (de) * 1972-02-05 1981-11-26 Robert Bosch Gmbh, 7000 Stuttgart Hydraulische Steuereinrichtung
DE2346845B2 (de) * 1973-09-18 1979-11-15 Schwing-Hydraulik-Elektronik Gmbh + Co, 4690 Herne Steuereinrichtung für die hydraulischen Antriebe eines Krans

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3176954A (en) * 1961-04-13 1965-04-06 Ross Operating Valve Co Convertible valve assembly
US3556154A (en) * 1968-04-24 1971-01-19 Bosch Gmbh Robert Electrohydraulic control arrangement
US3628567A (en) * 1969-06-14 1971-12-21 Itt Power control valve
US3768375A (en) * 1971-02-05 1973-10-30 Bosch Gmbh Robert Control apparatus for a hydraulic consumer motor
US3744374A (en) * 1971-03-17 1973-07-10 Bosch Gmbh Robert Hydraulic valve control apparatus

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4282901A (en) * 1978-07-18 1981-08-11 Diesel Kiki Co., Ltd. Proportional control type remote-control direction switching control valve device
US4605042A (en) * 1983-11-09 1986-08-12 Hydrino Ab Pilot oil supply arrangement
US4516604A (en) * 1984-04-20 1985-05-14 Taplin John F Pilot operated supply and waste control valve
US5463931A (en) * 1993-07-07 1995-11-07 Voac Hydraulics Boras Ab Controller for a hydraulic motor
CN104481943A (zh) * 2014-12-12 2015-04-01 吕珩 一种液压单级减压系统
CN104989693A (zh) * 2015-08-13 2015-10-21 江苏甬金金属科技有限公司 一种钢卷运卷小车升降控制系统
US20190085876A1 (en) * 2016-03-24 2019-03-21 Tadano Ltd. Hydraulic system
US10837473B2 (en) * 2016-03-24 2020-11-17 Tadano Ltd. Hydraulic system

Also Published As

Publication number Publication date
SE417234B (sv) 1981-03-02
FR2319794B1 (de) 1982-08-06
JPS6118043B2 (de) 1986-05-10
SE7601860L (sv) 1977-01-30
FR2319794A1 (fr) 1977-02-25
DE2533829C2 (de) 1985-01-10
JPS5217172A (en) 1977-02-08
GB1543182A (en) 1979-03-28
DE2533829A1 (de) 1977-02-17

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